Symmetrical double aortic arch in a beagle puppy

Double aortic arch denotes the persistence of both fourth aortic arches and has been reported as 'very rare' in the dog. Most reported cases have been seen in German shepherd dogs. An eight-week-old, male, 1.5-kg beagle presented with a three-week history of regurgitation and dyspnoea. A barium oesophagram showed severe oesophageal constriction cranial to the base of the heart, and a provisional diagnosis of a persistent right aortic arch was made. A left-sided fourth intercostal thoracotomy was performed. The ligamentum arteriosum was ligated and divided. The oesophagus was seen lying on the right-hand side of the aorta. Postoperatively, the puppy deteriorated and was euthanized. Postmortem revealed a double aortic arch entrapping both the oesophagus and trachea. The inexperienced surgeon could consider computed tomography or angiography to determine the exact vascular ring, and other possible concurrent vascular anomalies present, before surgery.

Isolated endogenous endophthalmitis due to a sporodochial-formingPhialemonium curvatumacquired through intracavernous autoinjections

We report a case of endogenous endophthalmitis due to a sporodochial-forming species of Phialemonium curvatum. The infection led to the enucleation of the affected eye, but there was no evidence of systemic dissemination. The isolated P. curvatum produced aggregates of phialides, many occurring on coils or in verticils, which eventually develop into sporodochia. The initial and post-enucleation isolates revealed they were identical to strains of P. curvatum from Israel causing disseminated disease in patients practicing intracavernous autoinjections for the treatment of erectile dysfunction. The reported case had unusual clinical and microbiological features. Despite the route of acquisition and the lack of systemic antifungal therapy, the infection did not spread beyond the eye. The morphology of the phialides aggregates was also unique, and the distinction between Volutella and Acremonium is discussed. This case expands the spectrum of infections due to Phialemonium species, and reveals a novel way of developing fungal endophthalmitis.

Characteristics of candidaemia with Candida-albicans compared with non-albicans Candida species and predictors of mortality

Candidaemia due to non-albicans Candida species is increasing in frequency. We describe 272 episodes of candidaemia, define parameters associated with Candida albicans and other Candida species, and analyse predictors associated with mortality. Patients with C. albicans (55%) had the highest fatality rate and frequently received immunosuppressive therapy, while patients with Candida parapsilosis (16%) had the lowest fatality and complication rates. Candida tropicalis (16%) was associated with youth, severe neutropenia, acute leukaemia or bone marrow transplantation, Candida glabrata (10%) was associated with old age and chronic disease, and Candida krusei (2%) was associated with prior fluconazole therapy. The overall fatality rate was 36%, and predictors of death by multi-variate analysis were shock, impaired performance status, low serum albumin and congestive heart failure. Isolation of non-albicans Candida species, prior surgery and catheter removal were protective factors. When shock was excluded from analysis, antifungal therapy was shown to be protective. Unlike previous concerns, infection with Candida species other than C. albicans has not been shown to result in an increased fatality rate.

Reduced infection and protection from clinical signs of cerebral neosporosis in C57BL/6 mice vaccinated with recombinant microneme antigen NcMIC1

NcMIC1 is a 460 amino acid Neospora caninum microneme protein implicated in host cell adhesion and invasion processes. In this study, we assessed the potential protectivity of NcMIC1-based vaccination against experimental N. caninum infection in mice, employing both recombinant antigen vaccines and DNA vaccines. Recombinant NcMIC1 (recNcMIC1) was expressed in Escherichia coli as gluthatione-S-transferase-fusion protein. The corresponding NcMIC1 cDNA was cloned into the pcDNA3.1 expression plasmid (pcDNA-MIC1), and expression was checked in transfected Vero cells. Mice (10 animals/group) were vaccinated either with recNcMIC1 antigen suspended in Ribi-adjuvant (3 intraperitoneal injections), pcDNA-NcMIC1 (3 intramuscular injections), or pcDNA-NcMIC1 (twice intramuscularly), followed by 1 intraperitoneal recNcMIC1 antigen boost. Control groups included corresponding treatments with adjuvant, pcDNA3.1 without insert, and PBS (= infection control). All vaccinated and control groups were then challenged intraperitoneally with 2 x 10(6) N. caninum tachyzoites. Animals were inspected daily for a period of 3 wk postinfection (PI). At day 21, all animals were killed and assessed for infection. Before day 21 PI, clinical signs such as walking disorders, rounded back, apathy, and paralysis occurred in infection controls (50% of the mice), pcDNA and adjuvant controls (20% each), and the combined pcDNA-NcMIC1/recNcMIC1-treated group (30%). No clinical symptoms were observed in the recNcMIC1 and pcDNA-NcMIC1 vaccinated groups. All mice were positive for cerebral N. caninum infection as assessed by PCR of brain tissue. However, quantitative real-time PCR revealed that the infection intensity was significantly reduced in the group vaccinated with recNcMIC1 antigen. Immunohistochemistry confirmed these findings. In contrast, the infection intensity was highest in the group vaccinated with the pcDNA-NcMIC1/recNcMIC1 combination, indicating that the sequential application of the DNA vaccine and recombinant antigen had a deleterious effect. Serological analysis showed that only recNcMIC1-immunized animals generated detectable antibody levels recognizing native NcMIC1. Thus, of all protocols applied here, only recNcMIC1 vaccination appears to be suited to reduce cerebral infection in mice challenged with N. caninum tachyzoites.

First report of suspected ethylene glycol poisoning in 2 dogs in South Africa

Ethylene glycol (anti-freeze) toxicity is a serious emergency in both veterinary and human medicine. Ethylene glycol (E/G) is the active anti-freeze principle in radiator water additives. It is odourless, colourless and has a sweet taste. As little as 5 ml or 20 ml is sufficient to kill a cat or a dog, respectively. Ethylene glycol is rapidly absorbed and metabolised in the liver to oxalate, which is deposited as calcium oxalate in the kidneys causing irreversible damage. This report describes 2 dogs that were suspected to have ingested ethylene glycol. The report contains a description of the 3 stages of ethylene glycol toxicity as well as a short discussion of the treatment. Public awareness about the dangers of anti-freeze will help in limiting exposure of pets and humans to this potentially fatal toxin. Veterinarians need to be aware of anti-freeze toxicity as delayed recognition and treatment will lead to the death of the patient.

Predictors of adverse outcome from candidal infection in a tertiary care hospital

OBJECTIVES

To retrospectively delineate predictors of adverse outcome by looking at the demographic features, therapy and outcome of systemic candida infection in a large tertiary care university-affiliated medical center.

METHODS

We reviewed the clinical data on 186 inpatients with candidemia over a 6-year period. The major reason for their hospital admission was an underlying malignancy or an infection other than candidemia.

RESULTS

Candida albicans, tropicalis, parapsilosis, glabrata and krusei caused 54, 22, 13, 8 and 3% of the candidemia episodes, respectively. The overall mortality was 42% and it was highest in patients suffering from candidemia of the glabrata species (73%). Forty-eight (63%) of the 76 patients who received no anti-fungal treatment died compared to 38 (34%) of 110 patients who were treated (P < 0.05). Predictors of adverse outcome were intensive care unit stay, renal failure, thrombocytopenia and the need for mechanical ventilation or inotropic support.

CONCLUSIONS

We identified four predictors of mortality from candidemia infection. Their validity should be further assessed and the specific candida strains and their susceptibility need to be methodically identified. Our data support immediate initiation of therapy at first identification of infection.

Slik Sterile-20 kinase regulates Moesin activity to promote epithelial integrity during tissue growth

The Drosophila Sterile-20 kinase Slik promotes tissue growth during development by stimulating cell proliferation and by preventing apoptosis. Proliferation within an epithelial sheet requires dynamic control of cellular architecture. Epithelial integrity fails in slik mutant imaginal discs. Cells leave the epithelium and undergo apoptosis. The abnormal behavior of slik mutant cells is due to failure to phosphorylate and activate Moesin, which leads to excess Rho1 activity. This is distinct from Slik's effects on cell proliferation, which are mediated by Raf. Thus Slik acts via distinct pathways to coordinate cell proliferation with epithelial cell behavior during tissue growth.

Tissue culture and explant approaches to studying and visualizing Neospora caninum and its interactions with the host cell

Neospora caninum is an apicomplexan parasite first mentioned in 1984 as a causative agent of neuromuscular disease in dogs. It is closely related to Toxoplasma gondii and Hammondia heydorni, and its subsequent description in 1988 has been, and still is, accompanied by discussions on the true phylogenetical status of the genus Neospora. N. caninum exhibits features that clearly distinguish this parasite from other members of the Apicomplexa, including distinct ultrastructural properties, genetic background, antigenic composition, host cell interactions, and the definition of the dog as a final host. Most importantly, N. caninum has a particular significance as a cause of abortion in cattle. In vitro culture has been indispensable for the isolation of this parasite and for investigations on the ultrastructural, cellular, and molecular characteristics of the different stages of N. caninum. Tissue culture systems include maintenance of N. caninum tachyzoites, which represent the rapidly proliferating stage in a large number of mammalian host cells, culture of parasites in organotypic brain slice cultures as a tool to investigate cerebral infection by N. caninum, and the use of techniques to induce the stage conversion from the tachyzoite stage to the slowly proliferating and tissue cyst-forming bradyzoite stage. This review will focus on the use of these tissue culture models as well as light- and electron-microscopical techniques for studies on N. caninum tachyzoites and bradyzoites, and on the physical interactions between parasites and host cells.

Identification and characterization of a Neospora caninum microneme-associated protein (NcMIC4) that exhibits unique lactose-binding properties

Microneme proteins have been shown to play an important role in the early phase of host cell adhesion, by mediating the contact between the parasite and host cell surface receptors. In this study we have identified and characterized a lectin-like protein of Neospora caninum tachyzoites which was purified by alpha-lactose-agarose affinity chromatography. Upon separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, this lactose-binding protein migrated at 70 and 55 kDa under reducing and nonreducing conditions, respectively. Immunofluorescence and immunogold electron microscopy with affinity-purified antibodies showed that the protein was associated with the tachyzoite micronemes. Mass spectrometry analyses and expressed sequence tag database mining revealed that this protein is a member of the Neospora microneme protein family; the protein was named NcMIC4 (N. caninum microneme protein 4). Upon two-dimensional gel electrophoresis, NcMIC4 separated into seven distinct isoforms. Incubation of extracellular parasites at 37 degrees C resulted in the secretion of NcMIC4 into the medium as a soluble protein, and the secreted protein exhibited a slightly reduced M(r) but retained its lactose-binding properties. Immunofluorescence was used to investigate the temporal and spatial distribution of NcMIC4 in tachyzoites entering their host cells and showed that reexpression of NcMIC4 took place 30 min after entry into the host cell. Incubation of secreted fractions and purified NcMIC4 with Vero cells demonstrated binding of NcMIC4 to Vero cells as well as binding to chondroitin sulfate A glycosaminoglycans.

A retrospective case series of computer-controlled total intravenous anaesthesia in dogs presented for neurosurgery

This article describes the anaesthetic management and use of total intravenous anaesthesia (TIVA) for neurosurgery in 4 dogs. Propofol in conjunction with morphine was used for the maintenance of anaesthesia. Anaesthesia was induced with either thiopentone or propofol. The program Stelpump (a target-controlled infusion program) was run on a laptop and connected to a syringe driver via an RS 232 cable. The program was found to be reliable and safe for the administration of TIVA in dogs. Invasive monitoring was required in order to monitor cardiovascular changes during surgery. Ventilation was controlled to maintain the end-tidal carbon dioxide below 40 mm Hg. The anaesthesia was characterised by haemodynamic stability. The haemodynamic stability was probably the result of the choice of TIVA and balanced anaesthesia. Intracranial pressure and oedema was controlled with dexamethasone, mannitol and ventilatory management either in combination or alone. Three dogs survived to hospital discharge and 1 dog was euthanased 2 weeks later due to tumour metastasis. The development and characterisation of the anaesthetic effects of TIVA needs to be elucidated in order to provide clinicians with rational guidelines for the appropriate use of TIVA in veterinary medicine.

Disinfection with 10% povidone-iodine versus 0.5% chlorhexidine gluconate in 70% isopropanol in the neonatal intensive care unit

AIM

The finding that 10% povidone-iodine skin disinfectant may compromise thyroid function in premature infants prompted its replacement with 0.5% chlorhexidine gluconate solution in 70% isopropanol. The objective of this study was to compare the incidence rates of true infection and contamination associated with the use of these two disinfectants in the neonatal intensive care unit.

METHODS

The study population comprised two cohorts of infants admitted to our neonatal intensive care unit: 1) in 1992-1993 when only 10% povidone-iodine was used as a skin disinfectant, and 2) in 1995-1996 when only 0.5% chlorhexidine gluconate solution in 70% isopropanol was used. A retrospective chart review was conducted to determine whether all documented positive blood, CSF and suprapubic aspirate cultures indicated true infection or contamination. True infection was defined as clinical symptoms and/or laboratory abnormalities suggestive of sepsis, with positive blood, CSF or suprapubic aspirate cultures.

RESULTS

1146 infants were admitted during the study periods, 507 during the first period and 639 during the second. In the early group, 17.6% of infants had major malformations, 72.0% were premature and 25.2% had weights of < 1500 g. Corresponding percentages for the latter group were 16.0%, 80.6% and 32.9%, respectively. No statistically significant differences were found between the two research periods in rate of infants with positive blood cultures, true infections, or contamination.

CONCLUSION

The use of 0.5% chlorhexidine gluconate solution in 70% isopropanol as a skin disinfectant is justified in neonatal intensive care units because it is not associated with an increased incidence of infections as opposed to 10% povidone-iodine and is devoid of detrimental effects.

Disinfection with 10% povidone-iodine versus 0.5% chlorhexidine gluconate in 70% isopropanol in the neonatal intensive care unit

AIM

The finding that 10% povidone-iodine skin disinfectant may compromise thyroid function in premature infants prompted its replacement with 0.5% chlorhexidine gluconate solution in 70% isopropanol. The objective of this study was to compare the incidence rates of true infection and contamination associated with the use of these two disinfectants in the neonatal intensive care unit.

METHODS

The study population comprised two cohorts of infants admitted to our neonatal intensive care unit: 1) in 1992-1993 when only 10% povidone-iodine was used as a skin disinfectant, and 2) in 1995-1996 when only 0.5% chlorhexidine gluconate solution in 70% isopropanol was used. A retrospective chart review was conducted to determine whether all documented positive blood, CSF and suprapubic aspirate cultures indicated true infection or contamination. True infection was defined as clinical symptoms and/or laboratory abnormalities suggestive of sepsis, with positive blood, CSF or suprapubic aspirate cultures.

RESULTS

1146 infants were admitted during the study periods, 507 during the first period and 639 during the second. In the early group, 17.6% of infants had major malformations, 72.0% were premature and 25.2% had weights of < 1500 g. Corresponding percentages for the latter group were 16.0%, 80.6% and 32.9%, respectively. No statistically significant differences were found between the two research periods in rate of infants with positive blood cultures, true infections, or contamination.

CONCLUSION

The use of 0.5% chlorhexidine gluconate solution in 70% isopropanol as a skin disinfectant is justified in neonatal intensive care units because it is not associated with an increased incidence of infections as opposed to 10% povidone-iodine and is devoid of detrimental effects.

Intracellular survival of persistent Group A streptococci in cultured epithelial cells

Group A streptococcus (GAS) is the principle etiologic agent of bacterial pharyngotonsillitis and a wide range of other diseases. Failure to eradicate GAS from patients has been documented in 5-30% of patients with pharyngotonsillitis, in spite of the continued sensitivity of GAS to penicillin and other beta-lactams. It was recently proposed that eradication failure might be attributed to the ability of GAS to maintain an intracellular reservoir during antibiotic treatment. We have previously shown that strains derived from patients with bacterial eradication failure, despite antibiotic treatment (persistent strains), adhered to and were internalized by cultured epithelial cells more efficiently than strains that were successfully eradicated. Since, penicillin and other beta-lactams do not penetrate well into mammalian cells, intracellular survival of GAS is crucial in order to persist during prolonged antibiotic treatment. In this study, we compared the survival of GAS strains from cases of eradication failure and eradication success, using an epithelial cell culture model. We found that persistent strains show significantly increased intracellular survival, compared to the 'eradication success' strains. This finding supports the idea that an intracellular reservoir of GAS plays a role in the etiology of antibiotic eradication failure.

Risk factors for the development of extended-spectrum beta-lactamase-producing bacteria in nonhospitalized patients

Although the risk factors for acquiring infection by extended-spectrum beta-lactamase (ESBL)-producing bacteria have been investigated in hospitalized patients, such risk factors have not been defined in the community setting. In this study, clinical data from a total of 311 nonhospitalized patients with community-acquired urinary tract infection (128 with ESBL-positive strains and 183 with ESBL-negative strains) were obtained. According to a multivariate analysis, the following were identified as independent risk factors: previous hospitalization in the past 3 months (OR=8.95, 95%CI, 3.77-21.25), antibiotic treatment in the past 3 months (OR=3.23, 95%CI, 1.76-5.91), age over 60 years (OR=2.65, 95%CI, 1.45-4.83), diabetes (OR=2.57, 95%CI, 1.20-5.51), male gender (OR=2.47, 95%CI, 1.22-5.01), Klebsiella pneumoniae infection (OR=2.31, 95%CI, 1.17-4.54), previous use of third-generation cephalosporins (P=0.014, OR=15.8, 95%CI, 1.7-143), previous use of second-generation cephalosporins (P<0.0001, OR=10.1, 95%CI, 4.2-24), previous use of quinolones (P=0.001, OR=4.1, 95%CI, 1.8-9.0), and previous use of penicillin (P=0.003, OR=4.0, 95%CI, 1.6-9.0).

Exogenous nitric oxide triggers Neospora caninum tachyzoite-to-bradyzoite stage conversion in murine epidermal keratinocyte cell cultures

Neospora caninum, like Toxoplasma gondii, undergoes stage conversion in chronically infected animals, and forms tissue cysts which contain the slowly proliferating bradyzoite stage. These tissue cysts are delineated by a cyst wall, protect the parasite from physiological and immunological reactions on part of the host, and bradyzoites remain viable within an infected host for many years. However, unlike T. gondii, N. caninum bradyzoites have been difficult to obtain using in vitro culture techniques, and current protocols, based on those developed for T. gondii, have been shown to be not very efficient in promoting tachyzoite-to-bradyzoite stage conversion. We report here an alternative in vitro culture method to obtain stage conversion of N. caninum from the proliferative to the cystic stage by using the Nc-Liverpool isolate, murine epidermal keratinocytes as host cells, and continuous treatment of infected cultures with 70 microM sodium nitroprusside for up to 8 days. This treatment significantly reduced parasite proliferation as assessed by Neospora-specific quantitative real-time PCR. The expression of bradyzoite markers was analysed by immunofluorescence following 4 and 8 days of in vitro culture using antibodies directed against bradyzoite antigen 1, the mAbCC2, and the lectin Dolichos biflorus agglutinin. Expression of the tachyzoite-specific immunodominant antigen NcSAG1 and the tachyzoite antigen NcMIC1 was also assessed. Transmission electron microscopy revealed that the majority of parasitophorous vacuoles were in the process of forming a distinct cyst wall through accumulation of granular material at the periphery of the vacuole, and parasites exhibited the typical features of bradyzoites. These findings demonstrate the usefulness of this culture technique as a promising way to study tachyzoite-to-bradyzoite stage conversion in N. caninum in vitro.

Efficacy and safety of a factor VIII-von Willebrand factor concentrate 8Y: stability, bacteriological safety, pharmacokinetic analysis and clinical experience

The present study was undertaken to evaluate stability, pharmacokinetic profile and efficacy of continuous infusion of 8Y in patients with different types of von Willebrand disease (vWD). Following reconstitution, 8Y levels of von Willebrand factor ristocetin cofactor (vWF:Rco), vWF antigen and factor VIII coagulant activity (FVIII:C) decreased to about 80% of the baseline levels; addition of low molecular weight heparin decreased the level of FVIII:C even further. Reconstituted 8Y was found to be sterile for up to 6 days postreconstitution. Ten vWD patients (four with type 2A, three with type 3, two with type 1 and one with 2N) underwent pharmacokinetic analysis. The recovery of vWF: RCo was significantly lower in patients with type 3 vWD (1.4 +/- 0.05% U(-1) kg(-1)) compared with that of the patients with types 1 (2.3 +/- 0.52% U(-1) kg(-1)) or 2A (2.0 +/- 0.06% U(-1) kg(-1)) vWD (P = 0.015). Type 3 vWD patients exhibited significantly higher vWF:RCo clearance (5.1 +/- 1.1 mL kg(-1) h(-1)) compared with that of patients with type 2A (2.8 +/- 0.7 mL kg(-1) h(-1)) and type 1 (2.6 +/- 1.0 mL kg(-1) h(-1)) vWD (P = 0.028). Accordingly, terminal half-life was lower in patients with type 3 vWD (8.0 +/- 0.6 h(-1)) compared with type 2A (12.7 +/- 5.9 h(-1)) or type 1 (14 +/- 1.2 h(-1)) vWD patients. Multimeric pattern of vWF from patients' plasma was similar to that of 8Y. In two patients treated with 8Y by continuous infusion for prevention or treatment of bleeding haemostasis was achieved. Thus, 8Y is suitable and haemostatically effective for continuous infusion treatment in patients with vWD.

Vero cell surface proteoglycan interaction with the microneme protein NcMIC(3) mediates adhesion of Neospora caninum tachyzoites to host cells unlike that in Toxoplasma gondii

Neospora caninum and Toxoplasma gondii are characterised by a very low host cell specificity, thus they are able to infect a wide range of different cells in vivo and in vitro. Infection of the host cell by tachyzoites is a process which is preceded by adhesion onto the host cell surface. The receptors on the host cell surface which would allow N. caninum to establish a physical interaction have not been investigated so far. Here we report the role of host cell surface proteoglycans as receptors for the adhesion of N. caninum tachyzoites to Vero cell monolayers. We found that N. caninum tachyzoites, similar to T. gondii tachyzoites, can bind to sulphated proteoglycans which naturally occur on the surface of mammalian cells, including heparin/heparan sulphate, chondroitin sulphates, as well as to the artificially sulphated glycosaminoglycan dextran sulphate. Although removal of heparan sulphate from the host cell surface results in decreased adhesion of T. gondii tachyzoites, binding of N. caninum tachyzoites is not affected by this treatment. Conversely, enzymatic removal of chondroitin sulphate A, B and C decreases N. caninum adhesion but does not affect T. gondii binding to Vero cells. Thus, T. gondii and N. caninum tachyzoites exhibit differential adhesive properties with regard to host cell surface glycosaminoglycans. Additional experiments employing Triton X-100 solubilised NcSRS2 and NcMIC3 showed that NcSRS2 binds to the host cell surface, but not through those sulphated glycosaminoglycans investigated in this study. In contrast, NcMIC3 binding to the host cell surface is dramatically influenced by these modifications. Further experiments showed that the NcMIC3 adhesive motif comprised of four consecutive epidermal growth factor-like domains expressed as a recombinant protein exhibits a high binding activity for sulphated glycosaminoglycans. These results suggest that host cell surface proteoglycan interaction of N. caninum differs from that observed for T. gondii, and that the epidermal growth factor-like adhesive motif in NcMIC3 could be involved in this process.

Identification of a Neospora caninum microneme protein (NcMIC1) which interacts with sulfated host cell surface glycosaminoglycans

The invasive stages of apicomplexan parasites enter their host cells through mechanisms which are largely conserved throughout the phylum. Host cell invasion is divided into two distinct events, namely, adhesion onto the host cell surface and the actual host cell entry process. The former is mediated largely through microneme proteins which are secreted at the onset of establishing contact with the host cell surface. Many of the microneme proteins identified so far contain adhesive domains. We here present the genomic and corresponding cDNA sequences coding for a 460-amino-acid (aa) microneme protein in Neospora caninum tachyzoites which, due to its homology to MIC1 in Toxoplasma gondii (TgMIC1), was named NcMIC1. The deduced NcMIC1 polypeptide sequence contains an N-terminal signal peptide of 20 aa followed by two tandemly internal repeats of 48 and 44 aa, respectively. Integrated into each repeat is a CXXXCG sequence motif reminiscent of the thrombospondin-related family of adhesive proteins. The positioning of this motif is strictly conserved in TgMIC1 and NcMIC1. The C-terminal part, comprised of 278 aa, was expressed in Escherichia coli, and antibodies affinity purified on recombinant NcMIC1 were used to confirm the localization within the micronemes by immunofluorescence and immunogold transmission electron microscopy of tachyzoites. Immunohistochemistry of mouse brains infected with tissue cysts showed that expression of this protein is reduced in the bradyzoite stage. Upon initiation of secretion by elevating the temperature to 37 degrees C, NcMIC1 is released into the medium supernatant. NcMIC1 binds to trypsinized, rounded Vero cells, as well as to Vero cell monolayers. Removal of glycosaminoglycans from the host cell surface and modulation of host cell surface glycosaminoglycan sulfation significantly reduces the binding of NcMIC1 to the host cell surface. Solid-phase binding assays employing defined glycosaminoglycans confirmed that NcMIC1 binds to sulfated glycosaminoglycans.

New carbon nanofiber/graphite felt composite for use as a catalyst support for hydrazine catalytic decomposition

Graphite felt supporting 40 nm diameter carbon nanofibers was synthesized and successfully used as a support for a high loaded iridium catalyst (30 wt%) in the decomposition of hydrazine; a strong mechanical resistance and a high thermal conductivity led to a very efficient and stable catalyst as compared to that used industrially, iridium supported on a high surface area alumina.

Invasive group A streptococcal infections in a large tertiary center: epidemiology, characteristics and outcome

BACKGROUND

Invasive group A streptococcal (GAS) infections are increasing alarmingly worldwide.

PATIENTS AND METHODS

To determine the clinical and epidemiologic characteristics of invasive GAS in a large tertiary medical center, we retrospectively surveyed microbiology and medical records of patients with invasive GAS infections (isolation of Group A Streptococcus from a normally sterile site) treated in our hospital from January 1995 to December 1997.

RESULTS

70 patients with a median age of 48 years (range 2 months-88 years) were identified. Of the 70 identified, 53 (76%) were adults (age > or = 19 years). The most common co-morbid diseases for invasive GAS in adults were diabetes mellitus, congestive heart failure (CHF), malignancy and immunosuppression. A probable port of entry was identified in 31 (44%) of the cases. In children, varicella lesions were the major port of entry. Overall mortality rate was 17%: The difference in mortality between pediatric and adult cases was significant (0/17 vs 12/53, respectively; p = 0.03). Toxic shock syndrome (TSS) and necrotizing fasciitis were identified in 8.6% and 5.7% of the cases, respectively, with mortalities of 83.3% and 25%. Hyponatremia and hypocalcemia were more frequently observed among the severely ill.

CONCLUSION

Invasive GAS infections tend to have an unexpected course and a broad clinical spectrum, ranging from local skin or pharyngeal involvement to deeply invasive fasciitis with TSS and high mortality. The elderly and those with underLying medical conditions are at utmost rsk for invasive GAS. Clear-cut guidelines for early therapeutic strategy, i.e. antibiotic administration and preemptive hospital admission are needed for community-based physicians.

Synthesis of CoFe2O4nanowire in carbon nanotubes. A new use of the confinement effect

Cobalt ferrite nanowires with an average diameter of 50 nm and lengths up to several micrometers were synthesized inside carbon nanotubes under mild reaction conditions using the confinement effect provided by the carbon tubular template.